Exploration der Grenzen der funktionellen Modifikation dünner magnetischer Schichten

Schirmer, B.

Dissertation / PhD Thesis/Book

Exploration der Grenzen der funktionellen Modifikation dünner magnetischer Schichten

Schirmer, B. (Corresponding author)FZJ*

1999
Forschungszentrum, Zentralbibliothek Jülich

Jülich : Forschungszentrum, Zentralbibliothek, Berichte des Forschungszentrums Jülich 3641, (1999) = Aachen, Techn. Hochsch., Diss., 1999

Please use a persistent id in citations: http://hdl.handle.net/2128/20370

Report No.: Juel-3641

Abstract: Novel properties and new applications have lead to a tremendous increase ofthe importance of thin films. In particular thin magnetic films have recently gained considerable interest. Such films show new phenomena such as giant magneto- resistance and oscillatory exchange coupling which enable new devices and applications. The significance of these effects is likely to increase in the future and with it the complexity of devices. Further improvements focus on the tailoring of thin films. To achieve this goal a deeper understanding of the interaction between structural and magnetic properties is essential. U nfortunately the sequence of layers in present magnetic sensor heads is too complex to isolate the infiuence of a specific interface. So the only promising approach to understand the different interface interactions is the usage of a model system. Depending on the specific aim of the investigation several systems can serve as a model. The aim of this work was to develop a thermodynamical model to describe the structural and magnetical properties of thin films. To develop this model the infiuence of epitaxial strain on the structure of thin films (FejCu3Au(100) and MnjCu3Au(100)) was investigated first. In a second step the infiuence of a magnetic interface on the structure of a metastable film was investigated. In this case FejNijCu(100) was chosen as a model system. Low- energy- electron diffraction I(V) measurements and full- dynamical I(V) calculations were used to determine the structure and magneto- optical- Kerr- effect measurements the magnetism of the model systems was investigated. The analysis of 3.3, 4.8, 18.7 and 53 ML thick films for the FejCu3Au system showed that all films have a non- pseudomorphic, tetragonally distorted structure. By astrain analysis this tetragonal distorted structures were identified as tetragonal distorted bcc structures. This structure analysis is in agreement with the prediction of the thermodynamic model. With the analysis of the structure of a 5.2 ML thick Mn film on CU3Au(100) it was shown that MnjCu3Au(100) has two pseudomorphic structures as a function of the film thickness. It was shown that the structure of the 16 ML thick Mn film could be attributed to a tetragonally distorted equilibrium structure for thin Mn films. A comparison with the thermodynamical model shows that the structure of the 5.2 and the 16 ML thick Mn film could not be understood by this model so far. So Mn thin films remain a mystery until furt her investigation of their elastical properties.

Note: Record converted from VDB: 12.11.2012
Note: Aachen, Techn. Hochsch., Diss., 1999

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